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Single- and multi-photon production in ee collisions at s√ up to 209 GeV

Research output: Contribution to journalJournal article

Published

Journal publication date05/2003
JournalEuropean Physical Journal C: Particles and Fields
Journal number1
Volume28
Number of pages13
Pages1-13
Original languageEnglish

Abstract

Events containing only energetic photons are analysed in a sample of 628pb−1 of data recorded from e+e− collisions at centre-of-mass energies between 189 and 209 GeV by the ALEPH detector at LEP. The e+e−→νν¯γ(γ) and e+e−→γγ(γ) cross sections are measured and found to be in agreement with the standard model predictions. The number of light neutrino generations is determined to be Nν=2.86±0.09 . Upper limits are derived on the cross sections for photon production in the context of several supersymmetric models. Limits are also set on the parameters of models with extra spatial dimensions, with contact interactions and with excited electrons.